Hydraulic pump



Jan. 24, 1967 L. E. CASS 3,299,633

ESTEFE 6455 'Z aljgm 64 162 65 0 /4 f4;

United States Patent This invention relates to a pump device 'and more specifically to a manually operable variable displacement pump device for use with a hydraulic system which is operable for power shifting apparatus such as outboard motors and the like.

An object of this invention is to provide a novel manually operable variable displacement pump device for a fluid pressure system of the type used for tilting a conventional outboard motor about a horizontal axis relative to its specific mounting.

A more specific object of this invention is to provide a manually operable variable displacement pump device for controlling the hydraulic actuating units used to tilt an outboard motor about its axis, in which the pump device includes a relatively large volume low pressure pump means for elevating the outboard motor to 'an operative position, and also includes a relatively low volume high pressure pump means for adjusting the angle of attack of the outboard motor during operation thereof.

A further object of this invention is to provide a novel and improved manually operable pump device, of the class described, which includes a single housing provided With a pair of displacement chambers and pistons of unequal size and each being selectively usable to control the hydraulic cylinder and piston units utilized in tilting an outboard motor about its horizontal transverse axis relative to its mounting.

These and other objects and advantages of the invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like character references refer to the same or similar parts throughout the several views, and in which:

FIG. 1 is a front perspective view of the invention;

FIG. 2 is a crosssectional view on an enlarged sc'ale taken approximately along line 2+2 of FIG. 3 and with certain parts thereof illustrated in adjusted position by dotted line configuration;

FIG. 3 is a front elevational view on the same scale as FIG. 2 and with certain parts thereof broken away for clarity;

FIG. 4 is a cross-sectional view taken approximately along line 4-4 of FIG. 3 and looking in the direction of the arrows; and

FIG. 5 is the transverse cross-sectional view taken approximately along line 55 of FIG. 4 in looking in the direction of the arrows.

Referring now to the drawings and more specifically to FIG. 1, it will be seen that one embodiment of my novel pump device designated generally by the reference numeral is thereshown. The pump device 10 is preferably used in a fluid pressure system such as that employed for tilting 'an outboard motor about a horizontal transverse axis relative to its mounting. In this type of fluid pressure system, the outboard motor is normally mounted by pivotal mounting means from the transom of a boat and a pair of hydraulic cylinder and piston units are employed to produce fore and aft swinging of the outboard motor about a transverse horizontal axis relative to its mounting. When the outboard motor is not being used, it is desirable to elevate the same about its transverse horizontal axis to an operative position to facilitate transportation of the boat.

It is also often desirable to slightly adjust the 'angulated relation of the motor about its transverse horizontal axis relative to the vertical to slightly alter the angle of attack 'ice,

of the motor during operation of the outboard motor. The pump device then is capable of permitting the various adjustments.

The pump device 10 includes a unitary housing 11 preferably formed of a cast metallic material such as aluminum, steel or the like. It will be noted that the housing 11 is of generally rectangular hollow configuration and includes a front wall 12, rear wall 12a, side walls 13, a bottom wall 14, and a top wall 15. The hollow interior of the housing 11 defines a reservoir chamber 16 which is adapted to contain a predetermined amount of hydraulic fluid. The top wall 15 is provided with an internally threaded filler opening 17 therein to permit hydraulic fluid to be conveniently introduced into the reservoir chamber 16 and this filler opening 17 is closed by a suitable threaded closure member 18.

Similarly, the bottom wall 14 of the housing is provided with an internally threaded drain opening 19 therein to permit hydraulic fluid to be drained from the reservoir chamber 16 and this drain opening is closed by suitable closure member 20 which threadedly engages the internal threads of the drain opening 19. The upper portion of the front wall 12 is provided with a pair of laterally projecting mounting flanges 21 and each is suitably apertured to facilitate mounting of the housing upon some suitable support structure of a small water craft or boat.

The housing 11 has a pair of elongate displacement chambers 22 and 23 respectively which extend forwardly from adjacent the rear wall 12a and both of these displacement chambers open exteriorly through the front wall 11. It will be noted that these displacement chambers are of circular cross-sectional shape and are of approximately the same length and are located on opposite sides of the reservoir chamber 16. However, it will also be noted that the chamber 22 is of greater diameter than chamber 23 as best seen in FIG. 2.

The displacement chamber 22 is connected in communicating relation to the valve chamber 25 by an inlet passage 24 which extends diagonally from adjacent the rear of the displacement chamber 22. Similarly, the displacement chamber 23 is interconnected in communicating relation by means of an inlet chamber 26 to a valve chamber 27. The valve chambers 25 and 27, respectively, are connected in communicating relation with the reservoir chamber 16 by means' of passages 28 and 29, respectively, also clearly shown in FIG. 2.

It is pointed out that the valve chambers 25 and 27 are formed in the rear wall 12 through a machining operation and each valve chamber 25 and 27 is closed with respect to the exterior by threaded closure plugs 30. It will be noted that the closure plugs 30 are of identical construction, each being externally threaded for threadedly engaging the internally threaded bore of the associated valve chamber. Each closure plug 30 has a sealing ring 31 formed of a compressible material interposed against an annular shoulder in the rear wall circumscribing the threaded bore therein and the head of the associated closure plug 30. Thus, each of the valve chambers 25 and 27 are sealed with respect to the exterior.

It will be noted that each of the closure plugs 30 has a hollow interior 32 which terminates in a reduced portion 33 so that an annular shoulder 34 is defined therebetween. Each valve chamber is provided with an elongate generally cylindrically shaped valve element 35 positioned therein and each of these valve elements has a rearwardly opening recess therein for accommodating one end of an elongate spring, the other end of this spring being disposed within the reduced hollow portion 33 of the associated plug 30.

The forward end portion 37 of each valve element 35 is of conical configuration and is normally urged into engaging relation with the frusto-conical surface of the associated valve chamber to thereby normally close the valve chamber with respect to the reservoir chamber 16. Each valve element is provided with an O-ring adjacent the forward end portion thereof to effect a seal between the valve chamber and the associated passage leading to the reservoir chamber 16.

It will be noted, however, that the valve elements 35 may retract rearwardly into the hollow interior 32 of the associated closure plug 30 in response to a positive pressure asserted against the forward portion of the valve element. Thus, it will be seen that the reservoir chamber 16 is normally closed with respect to the displacement chambers 22 and 23, but will be intercommunicated therewith when these displacement chambers are subjected to a negative pressure whereby the valve elements 35 will retract and permit the hydraulic fluid to flow into the associated displacement chamber.

An elongate generally cylindrically shaped piston 39 is positioned within and is axially shiftable relative to the displacement chamber 22. The piston 39 projects exteriorly of the housing 11 and has an actuating knob 40 secured thereto. A hearing and guide sleeve 41 having an outwardly turned annular flange 42 integrally formed therewith is secured to the front walls of the housing 11 by any suitable securing means such as bolts and the like so that the sleeve is disposed in coaxial relation with respect to the displacement chamber 22. Suitable seal means are provided including an annular retaining washer 43 disposed in butting relation with respect to the shoulder defined by an enlarged terminal portion of the displacement chamber 22. An O-ring 44 is interposed between the washer 43 and the end of the bearing sleeve 41, whereby upon axial movement of the displacement piston 39, hydraulic fluid will be prevented from escaping around the piston to the exterior.

An elongate generally cylindrically shaped piston 45 is positioned within the placement chamber 23 and is axially movable therein and projects exteriorly therefrom, the exterior terminal portion thereof being provided with an actuating knob 46. A hearing sleeve 47 having an annular flange 48 integrally formed therewith is secured to the front wall of the housing 11 by suitable bolts or the like whereby the bore of the sleeve is disposed in coaxial relation with respect to the displacement chamber 23. It will be seen that the bearing sleeve 47 serves to guide and support the piston 45 during extension and retraction relative to the displacement chamber 23.

Sealing means are also provided for preventing the escape of oil along the piston 45 during extension or retraction thereof, and this seal means includes a retaining washer 49 and an O-ring 50 interposed between the sleeve 47 and a shoulder defined in a terminal portion of the displacement chamber 23.

It will therefore be seen that when either of the pistons 39 or 45 are retracted or moving in a forward direction from the position illustrated in full line configuration of FIG. 2, the associated valve element 35 will unseat in response to the negative pressure produced in the associated displacement chamber and will allow the hydraulic fluid to flow from the reservoir chamber 16 into a displacement chamber.

Referring again to FIG. 2, it will be seen that the housing 11 is provided with a pair of spaced apart expansion chambers 51, each of which extends from the front wall of the housing and terminates in reduced rear portion 52. These expansion chambers 51 are closed with respect to the exterior by suitable closure members or plugs 53. It will be seen that the reduced rear end portion 52 of one of the expansion chambers 51 is connected by a passage 54 to the displacement chamber 22 while the other expansion chamber is intercommunicated with the displacement chamber 23 by a passage 55. Actually, the passages 54 and 55 are formed in a machining operation through the respective side walls 13 of the housing and the exterior openings of these passages are suitably closed by closure plugs. With this particular arrangement, hydraulic fluid may be introduced from the displacement chambers 22 and 23 into the expansion chambers 51.

Referring now to FIGS. 3, 4 and 5, it will be seen that the housing 11 is provided with an elongate transfer passage 56 extending transversely of the housing adjacent the front thereof and is connected in communicating relation with the expansion chambers 51. It will be seen that one end of the transfer passage 56 is connected to an elongate passage 57 which extends in a fore and aft direction and is connected at its rearmost end to a discharge port 58. The discharge port 58 is internally threaded and has secured thereto a conventional fitting 59. The fitting 59 is connected to a conduit (not shown) which is also connected to an accumulator that supplies the hydraulic fluid to a pair of cylinder and piston actuators used to tilt the outboard motor.

It will be noted that the other end of the transfer passage 56 is connected in communicating relation to a return passage 60 having a transversely extending ter minal portion 61 which communicates with the reservoir chamber 16. It is pointed out that the passages 57, 60 and the terminal portion 61 with the passage 60 are all formed by a machining operation and the respective exterior opening terminal portions of these passages are closed by suitable closure plugs as clearly seen in FIG. 4.

Valve mean-s are provided for opening and closing the return passage 60 with respect to the transfer passage 56. This valve means includes a threaded valve member 62 which threadedly engages the threaded recess in one of the side walls 12 of the housing 11. The valve member 62 is provided with a jam or stop nut 63 which limits inward movement of the valve member, and an actuating knob 64 is secured to the exterior terminal portion of the valve member.

An O-ring seal element 64 is positioned exteriorly of the threaded portion of the valve member 62 and serves to prevent the escape of hydraulic fluid from the housing during actuation of the valve member. The inner terminal portion of the valve member 62 is of reduced size and this terminal portion 65 engages a small ball type check valve 66 positioned adjacent the end of transfer passage 56. This ball check valve is shiftable in response to axial movement of the valve member to selectively close the transfer passage with respect to the return passage, and is also shiftable to permit intercommunication of the transfer passage with respect to the return passage.

During operation of the pump device, the outlet fitting 59 will be connected to an accumulator structure by means of a suitable conduit and the accumulator will be connected to each of the piston and cylinder units associated with the outboard motor by other pairs of conduits. Suitable valve means will be provided for controlling the flow of hydraulic fluid selectively to opposite sides of the piston in the cylinder and piston units associated with the outboard motor and these valve means will also be operable to prevent accidental downward movement of the outboard motor when the same is held in elevated position by such cylinder and piston units.

If the outboard motor is in the lowered operative position, and it is desirable to elevate the same to an inoperative position, the piston 39 will be reciprocated until the outboard motor is raised to the desired height. It will be noted during each retractive movement of the piston 39, a negative pressure will be produced in the displacement chamber 22, whereby the positive pressure within the reservoir chamber 16 will cause the valve element 38 to retract and intercommunicate the passage 28 with the passage 24. Upon the return stroke of the piston 39, the hydraulic fluid will not be able to re-enter the reservoir chamber 16 through the passage 28 since both the spring pressure and the pressure of the hydraulic fluid will cause valve element 35 to close the passage 28. To this end it is pointed out that the surface of valve element 35 which is facing the passage 28 as well as a portion of the O-ring surface associated therewith, will be subjected to a different pressure than the rear surface portion of the valve element 35 during reciprocation of the piston 39. Withdrawal of the piston 39 from its chamber 22 constitutes the suction stroke and the expected pressure differential results in the unseating of the valve and permits the flow of the hydraulic fluid into the displacement chamber 22. However, on the return or pressure stroke of the piston, the hydraulic fluid will be forced against the rear surface of the valve element 35 and the pressure produced thereby as well as the action of the spring 33 close the passage 28 and permit discharge of the fluid through the discharge outlet. The hydraulic fluid will therefore pass through the passage 54 into the expansion chamber 51 and then into the passage 56, thereafter into passage 57, and will be discharged through the discharge port to the accumulator. By increasing the pressure in the accumulator, the hydraulic fluid can be directed into the cylinder and piston units through the proper valves to cause extension of the pistons and result in pivotal elevation of the outboard motor about its horizontal transverse axes. Thus, an operator may reciprocate the piston 39 several times and the displacement of hydraulic fluid from the reservoir chamber and from the chamber 22 is of suflicient volume to permit raising of the outboard motor.

In the event that it is desirable to allow the hydraulic fluid to return to the reservoir chamber 16, the valve member 62 may be revolved in a direction to retract the same and permit the check ball 66 to be moved out of obstructing relation with respect to the return passage 60. It is pointed out that during initial operation of the pump device, the valve member 62 will be adjusted so that the passage 60 is blocked with respect to the passage 56. Thus, the outboard motor may be lowered or moved to the operative position by adjusting the valve member 62 to thereby intercommunicate passage 60 with the transfer passage 56. It is pointed out that the valving mechanism associated with the accumulator must also be adjusted when the outboard motor is raised or lowered.

Under certain circumstances, it is desirable during operation of the motor to adjust the angle of attack or vertical inclination of the outboard motor with respect to the vertical. Since the displacement chamber 22 and the piston 39 associated therewith displace a relatively large volume of hydraulic fluid during reciprocation of the piston 39, and since the outboard motor will exert a forward thrust against the piston and cylinder units associated therewith for tilting the same, it is desirable to use a high-pressure low volume displacement means to adjust the angle of attack of the motor during operation thereof.

Piston 45 is therefore reciprocated and it will be seen that during each retraction stroke, fluid will be introduced into the displacement chamber 23 and during each return stroke, fluid will be discharged therefrom through the passage 55 into the expansion chamber 51, thereafter into the transfer passage 56, then through a passage 57 and finally through the discharge port 58. The amount of hydraulic fluid discharged by reciprocation of the piston 45 is relatively small compared to the volume displacement of the piston 39, but, of course, a relatively high pressure is produced in the system by reciprocation of the piston 45. Therefore, the outboard motor may be adjusted slightly with respect to its vertical inclination by reciprocating the piston 45. It is pointed out that a relatively larger number of strokes of the piston 45 and a greater length of time is necessary to produce only the small amount of movement of such an outboard motor in such an adjustment operation.

It will therefore be seen that operation of the high pressure displacement piston 45 in the chamber 23 permits adjustment of the motor even during operation thereof since the forces multiplied are substantially greater than that of the other piston and displacement chamber.

From the foregoing, it will be seen that I have provided a novel manually operable pump device which may be very advantageously incorporated in a fluid pressure system of the type used to pivotally swing a conventional outboard motor about a horizontal transverse axis relative to its mounting.

It will be noted that my novel pump device is selectively operable to raise and lower the outboard motor, or to permit the angle of attack of the motor to be adjusted during operation of the outboard motor.

Therefore, it will be seen that I have provided a novel pump device which is not only of simple and inexpensive construction, but one which functions in a more efficient manner than any heretofore known comparable devices.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of my invention.

What is claimed is:

1. A variable displacement pump device for use in variously controlling a hydraulic cylinder and piston actuator units connected with a conventional outboard motor for tilting the same relative to its mounting about a horizontal transverse axis, said device comprising:

a housing structure having a reservoir chamber therein adapted to contain a predetermined amount of hydraulic fluid,

a first recess in said housing defining a low pressure large volume displacement chamber,

a second recess in said housing of substantially smaller volumetric space than said first recess and defining a high-pressure, low-volume displacement chamber,

a pair of manually operable elongate displacement pistons each being reciprocable within one of said displacement chambers, said displacement piston within said low-pressure, high-volume chamber being substantially larger than the'piston within the high-pressure, low-volume chamber, each of said pistons having one end thereof projecting exteriorly of the housing structure, a pair of actuating members each being secured to one of said exteriorly projecting ends of the pistons, each |piston being substantially smaller in cross-sectional size than the associated displacement chamber,

a pair of passages in said housing, each interconnecting said reservoir chamber and one of said displacement chambers,

a pair of substantially identical pressure responsive valve members each normally closing one of said passages, and opening its associated passage in response to a reduction of fluid pressure in the associated displacement chamber,

a discharge port in said housing connectible in communicating relation with cylinder and piston actuator units which are connected to the outboard motor for adjustably tilting the same about a transverse horizontal axis,

a transfer passage in said housing interconnected in communicating relation with said displacement chambers and being interconnected in communicating relation with said discharge port, whereby fluid introduced into a selected displacement chamber during the retraction stroke of the associated piston will be directed through the discharge port during the return stroke of said last mentioned piston,

a pair of similar exipansion chambers each being interposed between and interconnected to one of said displacement chambers and said transfer passage,

7 i a return passage in said housing interconnecting said transfer passage in communicating relation with said reservoir chamber,

and an adjustable valve interposed in flow controlling relation between said transfer and return passages for selectively closing and opening said return passage with respect to said transfer passage.

2. The pump device as defined in claim 1 wherein said displacement chambers are of elongate cylindrical configuration and are of substantially the same length, the low-pressure, high-volume chamber being of greater cross-sectional size than the high-pressure, low-volume chamber.

3. The pump device as defined in claim 1 wherein said adjustable valve for selectively closing and intercommunieating said transfer passage with said return passage comprises .a valve element being movable to selectively close or open said return passage with respect to the transfer passages, and a manually operable actuator member 0peratively interrelated with said valve element for moving the same.

References Cited by the Examiner UNITED STATES PATENTS 1,016,692 2/1912 Joyce 6052 1,150,800 8/1915 'Aldrich 60-54.5 1,969,408 8/1934 Kramer et al. 60-52 2,434,282 1/1948 Mueller 6052 2,440,060 4/1948 Page 60-52 2,776,624 1/1957 Reinhard 6052 EDGAR W. GEOGHEGAN, Primary Examiner. 

1. A VARIABLE DISPLACEMENT PUMP DEVICE FOR USE IN VARIOUSLY CONTROLLING A HYDRAULIC CYLINDER AND PISTON ACTUATOR UNITS CONNECTED WITH A CONVENTIONAL OUTBOARD MOTOR FOR TILTING THE SAME RELATIVE TO ITS MOUNTING ABOUT A HORIZONTAL TRANSVERSE AXIS, SAID DEVICE COMPRISING: A HOUSING STRUCTURE HAVING A RESERVOIR CHAMBER THEREIN ADAPTED TO CONTAIN A PREDETERMINED AMOUNT OF HYDRAULIC FLUID, A FIRST RECESS IN SAID HOUSING DEFINING A LOW PRESSURE LARGE VOLUME DISPLACEMENT CHAMBER, A SECOND RECESS IN SAID HOUSING OF SUBSTANTIALLY SMALLER VOLUMETRIC SPACE THAN SAID FIRST RECESS AND DEFINING A HIGH-PRESSURE, LOW-VOLUME DISPLACEMENT CHAMBER, A PAIR OF MANUALLY OPERABLE ELONGATE DISPLACEMENT PISTONS EACH BEING RECIPROCABLE WITHIN ONE OF SAID DISPLACEMENT CHAMBERS, SAID DISPLACEMENT PISTON WITHIN SAID LOW-PRESSURE, HIGH-VOLUME CHAMBER BEING SUBSTANTIALLY LARGER THAN THE PISTON WITHIN THE HIGH-PRESSURE, LOW-VOLUME CHAMBER, EACH OF SAID PISTONS HAVING ONE END THEREOF PROJECTING EXTERIORLY OF THE HOUSING STRUCTURE, A PAIR OF ACTUATING MEMBERS EACH BEING SECURED TO ONE OF SAID EXTERIORLY PROJECTING ENDS OF THE PISTONS, EACH PISTON BEING SUBSTANTIALLY SMALLER IN CROSS-SECTIONAL SIZE THAN THE ASSOCIATED DISPLACEMENT CHAMBER, A PAIR OF PASSAGES IN SAID HOUSING, EACH INTERCONNECTING SAID RESERVOIR CHAMBER AND ONE OF SAID DISPLACEMENT CHAMBERS, A PAIR OF SUBSTANTIALLY IDENTICAL PRESSURE RESPONSIVE VALVE MEMBERS EACH NORMALLY CLOSING ONE OF SAID PASSAGES, AND OPENING ITS ASSOCIATED PASSAGE IN RESPONSE TO A REDUCTION OF FLUID PRESSURE IN THE ASSOCIATED DISPLACEMENT CHAMBER, A DISCHARGE PORT IN SAID HOUSING CONNECTIBLE IN COMMUNICATING RELATION WITH CYLINDER AND PISTON ACTUATOR UNITS WHICH ARE CONNECTED TO THE OUTBOARD MOTOR FOR ADJUSTABLY TILTING THE SAME ABOUT A TRANSVERSE HORIZONTAL AXIS, A TRANSFER PASSAGE IN SAID HOUSING INTERCONNECTED IN COMMUNICATING RELATION WITH SAID DISPLACEMENT CHAMBERS AND BEING INTERCONNECTED IN COMMUNICATING RELATION WITH SAID DISCHARGE PORT, WHEREBY FLUID INTRODUCED INTO A SELECTED DISPLACEMENT CHAMBER DURING THE RETRACTION STROKE OF THE ASSOCIATED PISTON WILL BE DIRECTED THROUGH THE DISCHARGE PORT DURING THE RETURN STROKE OF SAID LAST MENTIONED PISTON, A PAIR OF SIMILAR EXPANSION CHAMBERS EACH BEING INTERPOSED BETWEEN AND INTERCONNECTED TO ONE OF SAID DISPLACEMENT CHAMBERS AND SAID TRANSFER PASSAGE, A RETURN PASSAGE IN SAID HOUSING INTERCONNECTING SAID TRANSFER PASSAGE IN COMMUNICATING RELATION WITH SAID RESERVOIR CHAMBER, AND AN ADJUSTABLE VALVE INTERPOSED IN FLOW CONTROLLING RELATION BETWEEN SAID TRANSFER AND RETURN PASSAGES FOR SELECTIVELY CLOSING AND OPENING SAID RETURN PASSAGE WITH RESPECT TO SAID TRANSFER PASSAGE. 